Hello, Doneldon.  Thanks for the reply.  I have a few follow up questions.  When you say using a old power pack, do you mean I need to cut out the end or the tip of the power supply and expose the wire.  Then hook it up to the red wire.  It doesn't matter which one is positive or negative.  The min volts is 12 and max 24, is that correct?  Furthermore, I can also use a 12V battery and it doesn't matter positive or negative.  Is that correct?
Thanks again for the info, it really help!

Hi folks.  I just purchased the Digital Command Train set and the expander set.  I notice there is a remote turn out in expander set.  I didn't find any information in how to connect remote turn out to the Digital Commander.  Is it possible to use those remote turn out or I need to get the DCC turn out?  This is my first train set and I was hoping to set it up for my kids for the holiday.  Any help is appreciated.  Thanks in advance.